Not Applicable
1. Technical Field
This invention relates in general to air conditioning systems and, more particularly, to an angled ultraviolet light fixture.
2. Description of the Related Art
Over the last several years, the use of ultraviolet (UV) light in commercial and residential air conditioning applications has become more popular. A UV light source in the UV-C spectrum, specifically at 253.7 nm, and potentially UV light in other frequencies such as 187 nm, has been shown to be extremely effective in destroying bacteria and fungi in air conditioning systems.
During operation of an air conditioning system, water condenses on the heat exchanger (typically referred to as the condensing coil). The drain pan is situated below the coil and collects run-off from the coil. Because the cool and moist environmental conditions in the coil are conductive to microbial infestations, UV lamps are often used to illuminate the coil and drain pan. U.S. Pat. No. 5,817,276 to Fencl et al claims that the UV lamp should be oriented perpendicular to the fins of the coil for maximum reflection within the coil.
Mounting a substantially straight lamp perpendicular to the fins, however, has some significant shortcomings. First, in some orientations, the fins will be horizontal in relation to the drain pan. If a substantially linear UV lamp is mounted perpendicular to the drain pan, its effectiveness in killing bacteria in the drain pan may be reduced. Further, mounting a linear UV lamp perpendicular to the fins may result in the use of a relatively short UV lamp, which will not emit as much UV energy as would a longer lamp.
Therefore, a need has arisen for a method and apparatus for UV filtration that maximizes energy to the coil and drain pan for higher microbial efficacy.
In the present invention, an air conditioning system includes a heat exchanger having a substantially rectangular profile and a drain pan beneath the heat exchanger to collect condensation. A substantially linear germicidal tube emits energy to the heat exchanger and drain pan. The germicidal tube has a first end proximate a first corner of the profile and a second end proximate a second corner of the profile, wherein the first and second corners are opposite to one another.
The present invention provides significant advantages over the prior art. Importantly, a longer germicidal tube may be used for more effective control of microorganisms, particularly in the drain pan.